Well I picked up a few of these awhile back. I liked the 801 and 901 as they aren't too big. The 510 on the otherhand are rather large. I made an 801 to 510 adapter so I could use an 801 atty on my 510 detonator mod. I found a nice trick to make the adapters smaller is to use a dremel or other cutting tool to cut away some of the backend of you 2 connectors. Then solder them together and you end up with a rather small adapter if done correctly. I used 2 of the 510 connectors for making a couple of mini mag mods for my dad and step mom. they bent rather easy when trying to press them in place but once again if you cut the backend off with a dremel except this time leave the center pin sticking out it works great as the positive battery connector. if anyone is interested in seeing the smaller 801 adapter please send me a PM and I will upload some instructional photos.